In reply to all:
Just a bit of a follow up and some musings/observations. In the end I decided not to stay up over night anyway so the over night parking issue became a moot point. I left home early saturday and pulled into the Old Dungeon Ghyll NT parking at about 0750. Plenty of space there but also a number of cars already there that might have been there overnight, and some converted vans - with people getting out brushing their teeth and so on, so I'm sure had been there overnight. In my excitement at being back in the Lakes I hadn't read the guidebook description of the parking very well for Gimmer, so only at this point realised I probably should have parked at Stickle Barn parking instead, I walked the 500 mtrs or so down the footpath there. Coming into that NT carpark, there were also a number of camper of vans that seemed more likely to have been there overnight than had just arrived. So although the NT clearly says no overnight parking on their website, it doesn't seem to be enforced.
Perhaps because I had followed the long discussion on UKC about campervans a week or so ago, I noticed just how many vans there were parked not only in the car parks, but also at other points as I drove in and out of Langdale! I happened to see this on the Guardian the same day as well: https://www.theguardian.com/uk-news/2021/jun/26/can-the-british-countryside... It's interesting how quickly vans have become such an issue. Nothing even close to the level of #vanlifestupidity I saw a week ago at the parking area for Beeston Tor in the Manifold Valley, where two vans had not only parked diagonally taking up two parking space each and had left a space between them where they had put their camping chairs and so on and - best of all - were having a decent sized camp fire on the car park space, presumably with logs and sticks collected from the wood around!
Back to the Lakes, I met my mates up at Gimmer: they had already done two routes to get to the top by the time I got up there at 9 am! All together we Bracket and Slab Climb (VS 4b) which was fun. Then Simon had to leave, so Luke and I then did 'A' Route (S 4a) which was good as well although I thought maybe slightly more serious feeling than B&S. Luke decided to head off then as well, so in the evening sunshine I wandered over to Pavey Ark and scrambled up Jack's Rake - a route I've done before but working it out, I realised it is very nearly 31 years since I did it as 16 year old! Lovely sunshine and very quiet when I got up to the top.
Post edited at 15:35